Medical treatments for a vascular lesion which use a catheter are widely performed because they are less surgically invasive than other vascular lesion treatments. For example, in percutaneous transluminal coronary angioplasty, a balloon catheter is used to widen a lesion area of a coronary artery so as to improve bloodflow.
Progression of arterioscleosis results in calcification of the lesion area and forming of a hard site. In some such lesions, a dilation force of a balloon catheter is not sufficient to widen the calcified lesion area. As a medical device that is capable of performing treatment even in this case, it is known to use a scoring balloon catheter. The scoring balloon catheter has a knife-edge-shaped or linear blade provided on the balloon, and the blade produces cracks in the calcified site such that it is easy to dilate a lumen. In addition, other known devices for removing the calcified site or plaque include a cutter that rotates at a high speed, a rotary file, a transducer, and a laser cutter. One example of a balloon catheter provided with a blade is disclosed in U.S. Pat. No. 5,320,634.